fun main(){
    println("666")
    val student=Student()
    student.grade=5
    student.number="10086"
    student.name="哈哈哈"
    student.age=17
    student.eat()
    student.doHomework()
    student.readBooks()
    val cellphone=Cellphone("huawei",2399.00)
    val cellphone2=Cellphone("xiaomi",2399.0)
    println(cellphone2)
    println(cellphone)
    Singleton.singletonTest()
    listReadOnly() //只读集合
    mapReadOnly()
    listReadWrite()
    setReadOnly()
    upperWord()//转换为大写
    println(filterTest())//过滤并转换
    val text="放射疗法是喀麦隆是免费foam法律方面"
    val text2=""
    val txtLen=getTextLength(text)
    val txtLen2=getTextLength(text2)
    println(txtLen)
    println(txtLen2)
    println(getTextLength2())
}